The present invention relates to optical material compositions suitable for forming optical elements, as well as to optical elements using cured products of such optical material compositions. In particular, the present invention relates to material compositions having anomalous dispersion properties and optical lenses formed of cured products of such material compositions.
Significant effort has recently been devoted to developing smaller, higher performance optical systems for use in imaging modules including cameras, video cameras, camera-equipped cell phones and videophones. These optical systems increasingly employ aspherical lenses and lenses made of anomalous dispersion glass to correct various aberrations. Anomalous dispersion glass is a type of glass used to reduce chromatic aberration and particularly to correct secondary spectrum. Optical materials with anomalous dispersion properties enable designing of smaller, higher performance optical systems for optical instruments and are therefore highly useful.
Known types of anomalous dispersion glass include fluorophosphate-based, B2O3—Al2O3—PbO-based, SiO2—B2O3—ZrO2—Nb2O5-based and other optical glass materials. These anomalous dispersion glass materials need to be ground and abraded to make optical elements such as lenses.
Anomalous dispersion glass materials having low melting points have recently been developed. Such glass materials can be formed into optical elements by pressing at high temperatures. Furthermore, anomalous dispersion optical materials are proposed in JP-A-2006-145823 (U.S. Pat. No. 7,193,789) that are formed of a UV-curable resin or N-polyvinylcarbazole in which nanoparticles of TiO2, an inorganic oxide, have been dispersed.